Elevating mechanism and brake control for refrigerator shelf frames



April 17, 1951 D COLLINS 2,549,664

ELEVATING MECHANISM AND BRAKE CONTROL FOR REFRIGERATOR SHELF FRAMES FiLed April 6, 1945 3 Sheets-Sheet l Q D Inveniur fi ul Douglas Collins- April 17, 1951 co u s 2,549,664

ELEVATING MECHANISM AND BRAKE CONTROL FOR REFRIGERATOR SHELF FRAMES Filed April 6, 1945 3 Sheets-Sheet 2 fi ww Attorneys- April 17, 1951 D; COLLINS ELEVATING MECHANISM AND BRAKE CONTROL FOR REFRIGERATOR SHELF FRAMES v Filed April 6, 1945 Y 3 Sheets-Sheet 3 ll/IVIZWNA InveNtmlilugglas Collins Patented Apr. 17, 1951 ELEVATING MECHANISM AND BRAKE CONTROL FOR REFRIGERATOR SHELF FRAMES I Douglas Collins, Salisbury, N. 0.

Application April 6, 1945, Serial No. 586,899

18 Claims.

The higher efficiency and operational advantages of refrigerators of the type in which access to the refrigerating chambers is obtained from above through a top door over those in which access is afforded through a vertically disposed front door is well recognized by thosefamiliar with the construction and design of such equipment.

However the difficulties encountered in fulfilling the requirements of ease and convenience in gaining access to the supporting shelves particularly of domestic household refrigerators has so far retarded adoption of the top door type.

The object of the present invention is to solve these problems by providing a refrigerator embodying vertically movable shelf frames which are automatically moved to a position elevated above the refrigerating chambers under control of manually operated brake members, such movement being utilized to open the top door and thereby afford full access to all articles supported upon the shelves.

A further object is the provision of means for manually regulating the lifting force applied to the shelf frames in dependence upon the nature and the weight of the articles supported thereon. A still further object is to utilize a part of the energy delivered by the shelf elevating the moing qualities thereof and also to economize in the weight and the cost of the cabinet structure.

With these and other objects in view as will be apparent from the following description, the invention is illustrated in the accompanying drawings in which:

Figure 1 is a perspective view of the improved refrigerator illustrating one of the shelf frames in elevated position.

Figure 2 is a detail perspective view partly broken away of one of theshelf frames and related parts removed from the cabinet.

Figure 3 is a detail view of the interior of one corner of the cabinet showing the guide roller for one of the corner posts of the shelf frame.

Figure 4 is a detail vertical sectional view through the cabinet showing a guide pulley for one of the shelf frame elevating cables.

Figure 5 is a detail horizontal sectional view through a corner of the cabinet illustrating the upper pulley for guiding the elevating cable.

Figure 6 is a detail sectional view through the cabinet illustrating the brake controlling one of the shelf frames.

Figure 7 is a detail view through the lower portion of one of the corner posts of the shelf frame illustrating the manner in which the elevating cable is attached thereto.

Figure 8 is an enlarged detailed sectional view of the spring motor for elevating the shelf frame.

Figure 9 is a longitudinal sectional View through the device for moving the top door to closed position.

Figure 10 is a vertical sectional view through the pump operated by the shelf frame.

Figure 11 is a detail sectional view on an enlarged scale showing the upper part of the pump.

Figure 12 is a detail sectional view of the pump illustrating the sealing device therefor.

Referring to the drawings in detail, the numeral l5 designates the refrigerator cabinet which is provided at the bottom with lateral drawers l6 and a central bottom chamber I! for accommodating the freezing unit. The cabinet I5 is open at the top to afford access thereto and in-the embodiment of the invention illustrated two chambers for refrigerating purposes are provided and one central chamber for frozen food. Doors |8 for closing the open tops of the refrigerating chambers are hinged at their rear ends to the rear Wall of the cabinet I5 and the refrigerating chambers are preferably provided with window openings in which transparent panels |9 of some such material as Lucite are arranged.

A shelf frame designated generally at 20 is disposed within each of the refrigerating chambers and consists of vertical corner posts 2| secured in position by frame-like shelves 22, the shelves and posts being sealed or otherwise rigidly connected to form a unitary structure. Pulleys 23 mounted in brackets 23a attached to the cabinet walls are arranged in the four corners of each refrigerating chamber at points spaced below the open top and these pulleys enter slots 24 formed longitudinally in the posts 2| for the purpose of guiding the vertical movement of each shelf frame and also to provide guides for the four elevating cables 25 associated with the shelf frame. Guide rollers 26 mounted in brackets 26a attached to the cabinet walls are arranged at the corners of each chamber above the pulleys 23 and are provided with grooved surfaces engaging the corner posts 2| to further assist in guidin the vertical movement of each shelf frame.

One end of each group of cables 25 is secured at 21 to the lower ends of the corner posts 2| as shown in Figure 7 and passing upwardly through these hollow posts the cables are trained over the pulleys 23 and extend downwardly along the corners of the refrigerating chamber and over a second group of pulleys 28 located at the bottom of the chamber. The cables 25 extend inwardly from the pulleys 28 toward the center of the refrigerating chamber and each is wound upon and terminally attached to a drum 29.

The drum 29 constitutes part of the motor for elevating each shelf frame and as shown in Figure 8 the drum is mounted upon a shaft 313 secured by a bracket 3| to the central portion of the bottom of the refrigerating chamber. A coil spring 32 is housed within the drum I29 andcone end is attached at 33 to the drum. The opposite end of the spring is securedat' 34 to the shaft 35 on which the drum 29 is rotatably mounted and a worm wheel 35 is keyed to 'the shaft 30 and constitutes part of themechanism for regulating the tension of the spring. As will be understood the tension of the spring is so applied to the drum .29 as to normally tend to turn the latter in the direction for winding the cables 25 thereon so that a lifting force is applied to each of the four corners of the shelf frame through the cables which tends to move said shelf frames to elevated position.

By rotating the worm wheel 35 the tension of the spring 32 may be variedandthusthe force tending to elevate the shelf frame may be regulated as required in accordance with the weight and nature of the articles upported thereon. The teeth of the worm wheel v35 are engaged with a worm 36, the pitch of which is so chosen as to provide a non-reversible drive, that is to say, the rotary movement of the worm 36 may be imparted to the wheel 35but the torque applied to the wheel by the spring is incapable of revolvin the worm.

The worm 36 within each chamber .is vconnected by a flexible shaft 3! with. a. manually operable hand crank 38 located externallyof the cabinet within convenient reach and. by manipulation of the crank in one .directionbrthe other the lifting force applied to .each shelf frame may be varied as desired.

Each Shelf frame is normally preventedfrom moving upwardly under the influence of the spring motor by a friction .brake member 39.engaged with one of the corner pests .2.| .and :secured to a lever 40 pivotally mounted at 4| at a suitable point on the wall of the cabinet |5. The brake member 39 is normally held in engagement with the corner post bya spring 142 and the pivotal mounting 4| .of the lever is so disposed withrespect to the brake member and the corner post that the upward movement-of the shelf frame tends to increase the braking effect of the brake member and thereby arrest the ascending movement of the frame. The lever 40 is connected with a rod 43 projecting externally of the cabinet and connected with a button 44 for convenience in releasing the brake V and permitting the shelf frame to rise to the desired position.

The rear part of the shelf frame is provided with a pair of rollers 45 engaging the under side of the .door l8 whereby the latter is moved to open position during the upward movement of the shelf frame.

To increase the heat insulatin properties of thecabinet the portions thereof are all of double wall cellular construction forming a fluid tight internal chamber from which the air is withdrawn by the pump illustrated in detail .in Figures l0 and '11. The pump for creating and maintaining a partial vacuum in the wall chain bers 4? consists of a hollow piston 48 secured at 49 to the bottom of the cabinet l5 and a cylinder 50 secured at 5| to and movin with the shelf frame. The lower end of the cylinder is flanged and provided with sealing means 52 to form a fluid tight joint with the piston.

A sealing valve 53 is arranged in the upper end of the hollow piston 43 and is normally maintained in engagement with the seat 54 by a spring 55 confined by a retaining member 56. The purpose of the sealing valve 53 is to maintain the sub-atmospheric pressure in the chamber 41 and preventthe admission of air at atmospheric pressure. A valve 5'! for limiting the reduction of pressure in the chamber 41 is arranged in the top of =the =cylinder 50 and is normally retained inengagement with a seat 58 by a spring 59. Additional ports 60 are formed in the valve seat 58 and are controlled by agravity actuated check valve 6| permitting the escape of'air from the cylinder 50 as the shelf frame is lowered. The cylinder 50 is secured at 62"to the member 5| by which the pump is attached tot-he shelf frame and an air port 63is provided inthememberfii. For convenience in manually lowering each shelf frame and restoring the 'latterto its position within the refrigerating chamber, the top member of the shelf frame is formed with aforwardly and. downwardly projectingportion '65 which, as showninF-igure 1,.is located externally of the cabinet when the"d00rs"l"8 are closed.

Upon operation of one of the buttons '44 and release of the brake member 39 the relat'edshelf frame 25 is movedupwardly by the'cablcs 25 actuated by the spring motor driven drum '29.

During its ascending movement the shelf frame swings the door I8 to open position through'the rollers 45 and the shelf frame continues to rise until the movement thereof is arrested 'by'the brake member 39 upon release 'of the button '44. During the first stage of the upward movement of the'she'lf frame, the reduction in' pressure in the cylinder 5|] tendsto withdraw air'from the insulating chamber '41; the va1ve53 -opening and the valve 51 remaining closed under th'einfluence of the spring 59. When the pressure is reduced to a predetermined'value the 'tension'ofthe spring '59 is overcome 'and'the' valve-51 opens-admitting air to the space between theyalves53 and '57. It will be understood, however, that the valve 53 closes instantaneously thereby preventing the admission 'of air at atmosphericpressure to the chamber 41. During the "subsequent upward movement of the shelf frame the valve" 53' remains closed and the slow admission of 'air' to'the cylinder under control of thespring actuated'valve 5? acts to check or retard upward movement 'of the shelf frame. Further means such asdesignated at t5 in Figure l and illustrated in detail in-Figure 10 may be used in conjunction with the'vacuum pump or in substitution thereof in-casethe pump is not desired for yieldably retarding the upward movement of the-shelfframe. This retarding device consists -ofa cylinder-$|isecured at 61 to the cabinet I5 and apiston Tod 68 secured at 69 :to the top .-|8. NA piston 1.0 secured to the rod 68 ismoved in the cylinder'underthe influence of a spring 11. The tension of the spring H tends to maintain the door -|'8-.in-engagement with therollers .45 but during opening movement of the door under the influence of the elevating motorthe spring 7| is compressed but the slow escape offair througha port 12 in the cylinder retards the opening of the door l8 :rmountedbrake shoe normally but releasably engaged with a portion of said frame and effective in all vertical positions Of said frame to arrest upward movement thereof and with the distance from the point of pivotation of the shoe to the are described by the lower portion thereof being greater than the distance from the point of pivotation to the portion of the frame engaged by the shoe whereby upon any force moving the frame upwardly the shoe is moved upwardly into jamming engagement with the frame to frictionally engage the frame and prevent upward movement thereof, and means arranged externally of said cabinet for controlling the brake means.

2. In a refrigerator, a cabinet having an open top refrigerating chamber, .a door for the open top, a shelf frame vertically movable in said chamber, means constantly exerting a force sufficient to elevate the frame when loaded, and manually releasable brake means normally effective in all vertical positions of said frame to arrest movement of the frame in selected positions.

3. In a refrigerator, a cabinet having an open top refrigerating chamber, a door for the open top including marginal edge walls, a shelf frame vertically movable in said chamber, means constantly exerting a force sufficient to elevate the frame when loaded, manually operable means to releasably arrest movement of the frame in selected positions, and a handle on the top of said frame projecting outwardly therefrom and terminating in spaced relation to the frame a distance such that the handle projects beyond one of said edge walls of the door and said handle further having such dimensions as to extend externally of said cabinet when the door is closed on top of the frame.

4. In a refrigerator, a cabinet having an open top refrigerating chamber, a door for the open top, a shelf frame vertically movable in said chamber, means constantly exerting a force sufficient to elevate the frame when loaded, a manually operable member arranged externally of said cabinet, and means controlled by the member for regulating the force exerted by said force exerting means.

5. In a refrigerator, a cabinet having an open top refrigerating chamber, a pivotally mounted door for the open'top, a shelf frame vertically movable in said chamber, means constantly exerting a force sufficient to elevate the frame when loaded, means carried by the frame and cooper-' able with said door for swinging said door to open position during elevation of said frame, self energizing brake mechanism normally engageable with said frame to arrest upward movement thereof, means for releasing the brake mechanism to permit elevation of the frame to selected positions and means normally tending to close said door.

6. In a refrigerator, a cabinet having an open top refrigerating chamber, a shelf frame vertically movable in said chamber, spring means :constantly'exerting a force sufhcient to elevate the frame when loaded, and manually operable means for regulating the tension of the spring means to correspond with the load on said shelf frame.

7. In a refrigerator, a cabinet having an open top refrigerating chamber, a shelf frame vertically movable in said chamber, a spring motor, means actuated by said motor to elevate said frame, brake means normally effective in all vertical positions of said frame to arrest movement of said frame, and manually operable means to render the brake means ineffective whereby the shelf frame may be moved to the desired eletop refrigerating chamber, a shelf frame movable vertically in said chamber, and including slotted corner posts and rotatable guide members secured to the cabinet and partially engaged in the post slots.

9. In a refrigerator, a cabinet having an open top refrigerating chamber, a shelf frame movable vertically in said chamber and including slotted corner posts, and rotatable guide members mounted on the cabinet and partially engaged in the post slots, actuating cables attached at one end to the posts, extending upwardly therein over the guide members and downwardly in the corners of the chamber.

10. A refrigerator as claimed in claim 9 provided with a motor, and a drum driven by said motor to which the opposite ends of the cables are attached.

' a shelf frame vertically movable in the refrigerating chamber, force applying means tending to elevate said frame, and a pump operable by the upward movement of the frame to withdraw air from said internal chamber.

12. A refrigerator as claimed in claim 11 wherein said pump includes piston and cylinder elements, a valve preventing admission of air to the internal chamber, and means connecting the respective elements with the cabinet and frame.

13. A refrigerator as claimed in claim 11 wherein said pump includes a valve for determining the reduction in pressure in said internal chamber and operative when said pressure reaches a predetermined value to yieldably retard upward movement of said frame.

14. A refrigerator as claimed in claim 11 wherein said pump includes a hollow piston communicating with said internal chamber, a cylinder coacting with said piston, and valve means for determining the reduction in pressure in said internal chamber produced by operation of said pump.

15 A refrigerator as claimed in claim 11 wherein said pump includes a hollow piston connected to said cabinet and communicating with said internal chamber, a cylinder connected to said shelf frame and coacting with said piston,

valve means for determining the reduction in pressure in said internal chamber produced by operation of said pump, said pump being 0perative during the initial upward movement of the frame to withdraw air from the internal chamber, and said valve means being operative during the succeeding movement of the frame to yieldably retard said movement.

16. In a refrigerator, a cabinet having an open top refrigerating chamber, a shelf frame includring fverltical .;corner rposts vertically movable throughzthe open top. of'said chamber, azhinged door engaged and :swung by :said :frame to open position during the upward-movement :of .said

frame, means operative to close said door,;me.ans iacting in' opposition tov saidtclosingmeans and operative to elevate said frame, .andimanually operable means for releasably arresting movement of the frame in selected vertical positions including a self-energizingbrake mechanism nor- *ma-lly frictionally'engaging one of :said posts ;and effective-in allzvertical positions of the frameto arrest upward movement thereof anclrel'easable means 'controllingthe brake and effective upon operation to release the brake to permit elevention of said frame to selectedpositions.

17. "In a refrigerator, a cabinet having an open top refrigerating chamber; a door'for "the .open top, a shelf frame vertically movable insaid chamber, adjustable means constantly exerting a force sufficient to elevate the frame when loaded, manually settable means for adjusting the elevating means to vary the elevating force exerted on said frame, stop means normally effective to prevent upwardmovement ofthe frame,

and release means operative to render'the stop means inefiective whereby the frame may be elevated to a selected position by the force exerting means, the frame being stopped in the selected position by the stop means under control of the release means.

18. A shelf construction includin in combination a movable shelf irame'means constantlyapplying force to said frame to translate the same from its original position, a releasable self-energizing brake mechanism normally frictionally engaging a portion of said frame in opposition to said force applying means to prevent movement of; :sald::frame randcontrol :means for ,said brake mechanism effective :upon operation to release the braking action to permitvmovement of said frame as 10Ilg 'aS the brakingaction :is released frame.

, DOUGLAS COLLINS.

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